Early suppression, fast response, or ESPR, are ceiling-mounted sprinkler systems that started being used in warehouses around 1990 as an alternative to rack-mounted sprinkler systems. ESFR heads detect fire faster and are reported to start spraying with more speed than conventional sprinkler heads. They also output water at higher volumes (approximately 100 gallons per minute). Droplet size is typically bigger which delivers more water, with greater speed, to the fire source. ESFR systems reportedly extinguish fires faster and more effectively with less damage to product than in-rack systems.